Switching apparatus



1939. J. E. OSTLINE SWITCHING APPARATUS Filed June 12, 1937 INSULH 7'10 3% mm M U MIN 2 M WQ m mm 2 7 4 7 OJ r5 5 0 3g U Q (I) U m 3 m i 3 4 O 4 2 L W 63 6 M B 6 5 7 1 a m 6 56 73% 8 a 1 8 1175 01.17 770/! MENTOR.

JOHN E.OSTLINE BY 04 w, M

ATTORNEY 5.

Patented-Jan. 1c, 1939 2,143,572

UNITED STATES PATENT OFFICE SWITCHING APPARATUS John E. Outline, Chicago, Ill., asslgnor to Associated Electric Laboratories, Inc., Chicago, 111., a corporation of Delaware Application June 12, 1937, Serial No. 147,810

12 Claims. (Cl. 200-98) The present invention relates to switching apeach conductor of each line incoming and outparatus and more particularly to apparatus going therefrom, is connected to one of the adapted for use in wire communication systems wipers engaging with the contact segments operfor selectively setting up connections between ated by the control element.

5 the various lines embodied therein. It is an object of the present invention, there- 5 In the usual system of this character, and fore, to provide improved switching apparatus notably in an automatic telephone system of any of the general character described, wherein each size, a considerable number of switching units of the switchi s U e embodied therein is 0 are necessary for performing. the various line extremely simple, ugg d d C mp el0 selecting functions required in establishing -de-' ment, is economical in construction and faithsired connections between the many lines of the ful in operation, and wherein the units are system. Several types of switching units for susceptible of being easily mounted in a supportperforming the above noted functions are known l am so t a the p y a installed in the electrical arts. One form of unit which system utilizing the apparatus may be adjusted is well adapted for use in the application noted at will without disrupting the entire installation 15 and which possesses distinct advantages with by adding o removing units from the a respect to the simplicity of its construction, is More specifically, it is an object of the invenshown in United States Patent No. 1,201,869- tion to provide a system of the above character Reed, granted October 17, 1916. Briefly dewherein the control elements of the various units scribed, the unit disclosed in this patent comare operated by actuating means common t0 20 prises a circuit controlling element having plurality of the units. mounted thereon contact segments rotatable with In e e a the Objects as set forth ve a the controlling elementbetween two positions to in D attained in eeeel'dence with the P e make and break contact between a multiplicity lmlelltlen y Providing Switching pp u 00mof brushes or wipers, arranged in pairs respecprising a plurality of switching units each includ- 25 tively associated with the several segments, ing a movable circuit controlling element, a mov- Means comprising a magnet having an armature ab e m be for actuating t e e ements of the or plunger arranged to actuate the circuit con- Several unitsmeahe Selectively associating trolling element are provided in the unit for e elements with the actuating member to be rotating the element between its two operating actuated thereby, and means Comprising a D 30 positions. While this form of switching unit is of heavy duty ays for imparting movement fairly satisfactory in operation, the large number to the actuating e More specifically. each of wipers bearing against th Conta t segments switching unit circuit controlling element comand the construction of the segments necessitates 911565 a Shaft biased to a normal Position. Such the use of a heavy duty solenoid of comparathet the Contact Segments r ed t e y are tlvcly large size and requiring a, co id rabl positioned intermediate two sets of wipers comamount of power for its energization. In order prisms resilient o duc s fi edly mounted on to obviate this difliculty, an improved arrangethe frame of the unit and arranged in two rows ment disclosed in copendlng application s r l on either side of the contact segments. These No. 109,813-Obergfell, filed November 9, 1936, wipers are adapted to be connected to the con- 40 was developed. In the structure of the unit dlsductors of th in s outgoin from the unit and closed in this application, the elements are so to be engaged by t e Contact Segments when constructed and arranged that less power i r the control element is rotated in either of two q red to actuate the circuit controlling element directions to either 0! tWO Off-normal P ns embodied therein, whereby a heavy duty relay individually corresponding to the s pe s. 45

may be used for actuating this element. AJ- The conductors of the line incoming to the switch though the improvements as disclosed in the are p ed t be connected to the us Obergi'ell application renders a switching unit of tact segments by means compri i D s l! conthe form Just described practical from an operectors e ectrica ly connecte between e sea- 5 ating standpoint, the unit is relatively expensive ments and the line conductor terminals. The 60 to manufacture. due to the cost entailed in provarious switching units are arranged in a row viding the heavy duty relay. Moreover, with a within a mounting frame which also carries the unit of the term shown in this application deactuating member and the two solenoids for movsigned for a given line capacity, the construction ing this member. This member is adapted to be 66 is mparatively bulky because 01 the fact that associated in driving relation with selected ones of the control elements respectively embodied in the switching units by clutching means individual to each unit and controlled by small relays of standard construction also individually embodied in each unit.

The novel features believed to be characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further advantages and objects thereof, will best be understood by reference to the specification taken in connection with the accompanying drawing, in which Figure 1 illustrates switching apparatus constructed and arranged in accordance with the present invention and comprising a plurality of the improved switching units; Fig. 2 is a broken side view illustrating the details of one of the switching units shown in Fig. 1; Fig. 3 is a view partially in section taken along the lines 3-3 of Fig. 2; and Fig. 4 is a view illustrating the details of the clutching mechanism incorporated in the switching unit shown in Figs. 1 and 2.

Referring now more particularly to Fig. i of the drawing, the improved switching apparatus there shown and having embodied therein the features of the present invention comprises a frame Ill, divided into two sections ii and I2 for respectively accommodating a plurality of switching units l3, i4, 15, etc., and means common to these units for actuating the various circuit controlling elements thereof. The three units I3, i4, and I5 are shown as being mounted on the frame iii within the section H by means comprising bolts i3 and I1 extending through the top and bottom members 8 and 9, respectively, of the frame Hi. It is contemplated that with this arrangement the size of the section II for a frame l0 designed to accommodate the switching units for a particular installation shall be suflicient to accommodate the number of units ultimately required to serve the maximum estimated line capacity of the apparatus. Thus, if the apparatus is to be used in an automatic telephone system such, for example, as a system of the form disclosed and claimed in applicants copending application Serial No. 168,726 filed October 13, 1937, having a calculated ultimate capacity of one thousand lines and a present capacity of four hundred lines, the section I i will be made of suiiicient size to accommodate the required number of switching units for setting up connections between one thousand lines. At the time the system is installed, however, only the number of units required to serve the four hundred lines will be placed in service, the remaining portion of the section being left blank and additional switching units being inserted therein from time to time as the size of the exchange progressively increases. By this arrangement and due to the exceptionally small size of each of the units, it is possible simply and economically to enlarge the capacity of a wstem embodying the units as the need for enlargement arises and without disrupting or in any way modifying the apparatus already in service.

The actuating means for the various circuit controlling elements embodied in the several switching units comprises a member l3, slidably mounted in openings provided in the end and intermediate members i9, 20 and 2! of the frame Ill and having rigidly supported thereon a magnetic piece 22, which forms the armature for each of two actuating magnets 23 and 24 mounted respectively on the frame members 20 and 2| by means of screws 23 and 26. The actuating member I3 is restrained in a normal position when both of the two magnets 23 and 24 are deenergized by means comprising coil springs 21 and 23 cooperating respectively with pivoted arms 29 and 30 which bear against opposite sides of the armature piece 22. The arm 29 is pivotally mounted on the upper member of the frame Ill, and is limited in its movement to the left through the force exerted thereon by the spring 22 by a. stop pin 3| also mounted on the frame iii in any suitable manner. Similarly, the arm 33 is pivotally mounted on an extension 32 of the member 2i and is limited in its movement to the right under the force of the spring 23 by a stop pin 33 also supported on the frame it. It will be observed that the member I3 is movable in either of two directions depending upon which of the two magnets 23 or 24 is energized. Thus, if

the magnet 23 is energized it attracts the armature piece 22 to the left against the bias of the spring 23 to move the armature piece to the left. In a similar manner and with the member l3 and the armature piece 22 in the position shown, when the magnet 24 is energized these two members are moved to the right against the force exerted thereon by the spring 21. It is noted that the frame Hi, the member i8 and the armature 22 are all constructd of magnetic material, such, for example, as iron, thereby to provide a low reluctance substantially closed magnetic circuit for the flux produced when either of the two magnets is energized and to enhance the force exerted on the armature piece 22 following energization of either of the two magnets.

Referring now more particularly to Figs. 2, 3 and 4 of the drawing, wherein the switching unit indicated generally at i3 is shown in greater detall, this unit comprises a frame 34 having right angularly bent end portions 35 and 36, between wh ch the circuit controlling element comprising a shaft 31 is rotatably mounted. At its left end this shaft is supported by a bronze bearing cap 33, threaded into the end portion 36 and drilled to provide a bearing surface for the shaft. At its right end the shaft 31 is supported in a bearing surface formed by drilling the end portion 35 of the frame 34. Supported on and insulated from the shaft 31 by means comprising an insulating tube 33 are a plurality of contact segments 4i] alternated with a plurality of insulating washers 4i. For the purpose of fixedly positioning the segments 4|) on the shaft 37 there is provided a fiber key 42 which is adapted to rest in a key slot formed in the shaft and to extend through suitably formed key-ways cut in the tube 39, the segments and the washers 4i. The segments 40 and insulating washers 4i are pressed together against an annular ring 43 by means comprising a nut 44 threaded on the right extremity of the shaft. It will be noted that the ring 43 is fixedly mounted on the shaft 31 by a pin driven into a tapered drill hole extending through the ring and the shaft.

In assembling the elements referred to in the immediately preceding paragraph, the tube 39 is first slipped on the shaft 31 in abutting relation to the ring 43. Following this, the insulating washers 4| and segments 40 are slipped on the shaft over the insulating tube 39. The assembly is completed by inserting the key 42 in the keyway to alignthe various segments, and by screwing the nut 44 on the right end of the shaft to clamp the elements together, thereby to provide a rigid assembly.

Each of the contact segments 40 is electrically connected to aterminal 46 by a flexible pigtail connector 41, formed of copper braid or the like, soldered at its ends to the associated segment and terminal. As best shown in Fig. 3, the various terminals 46 are clamped between two members 48 and I9 constructed of insulating material by screws 60 extending through the two members noted and threaded into tapped drill holes provided in the frame 34. These terminals are adapted to be connected to the conductors forming the lines incoming to the switching unit. By this arrangement a switching unit of extremely small size for a given line capacity is obtained.

As shown more particularly in Figs. 2 and 3, each of the contact segments 40 is roughly triangular in shape, is rounded at its upper end, and is provided with a V-shaped groove, the sides of which form the contacting surfaces for engaging with either of two associated wipers. These wipers form two sets comprising respectively the resilient conductors i and 52 arranged in rows with their ends disposed on opposite sides of the contact segments. Preferably, these conductors are constructed of bronze or like resilient material and are supported on the frame 34 by clamping the same at the upper ends thereof between insulating members 53, 54 and 55. The members noted are clamped together and to the frame 34 by screws 55 extending therethrough and threaded into tapped drill holes provided in the frame 34. For the purpose of guiding the various wipers in their movement, there is provided intermediate the upper and lower ends thereof a guide member 51 of insulat ng material supported on the frame 34 by means comprising spacing members 58 located at each end of the member 51 and clamping screws 60. Each of the wipers 5| and 52 is tensioned or biased into engagement with this member and moves in a guide slot provided therein when engaged by its respective associated contact segment 40. The lower ends of the wipers BI and 52 are curved outward to insure a smooth engagement with the respective associated contact segments when the segments are rotated into engagement therewith. It will be observed that the V-shaped groove provided in the engaging end of each of the segments insures a two-point contact between the segment and its associated wipers. It will be observed further that during rotation of the segments 9. slidable engagement occurs between each segment and its respective associated wipers to provide a self-cleaning action of the contacting surfaces. Normally the segments are restrained in the position'shown in Fig. 3 of the drawing by means comprising a coil spring Bi connected between an arm 62 projecting from the annular ring 43 and an eye 53 clamped between the insulating members 48 and 49. From this normal position the shaft 21 is adapted to be rotated about its axis in either a clockwise or counterclockwise direction, thereby to bring the commutating segments 40 into engagement with the respective associated wipers 5i or 52 of the two wiper sets. Such rotation of the shaft 31 is accomplished through operation of the actuating member i3 from the normal position shown in Fig. 1 to one or the other of its two ofi-normal positions. To this end, and as best shown in Figs. 2 and 4, the member I8 is provided with a clutch projection 64 extending from the edge thereof, which projection is adapted to cooperate with a clutching element 65, slidable axially along the shaft 31, and normally restrained to the left out of engagement with the projection 54 by a coil spring 61, interposed between the clutching element and the annular ring 43 and enclosing the shaft 31. A pin 55, extending through a drill hole provided .in the shaft, engages the sides of a slot 68 cut in the shank portion 69 of the clutch element 65 to form a stop against which the element 65 is normally braced, to guide the element 55 in its movement axially along the shaft 31 and to provide means for mechanically coupling the element 65 with the shaft 31. The radially extending flange portion of the element 65 has formed at its lower end two fingers 10 and 1! within which the projection 54 on the member i8 is adapted to extend when the element 65 is moved to the right. It will be noted that the sides of the fingers 10 and TI for engaging the projection 64 are rounded so that when the member 18 is moved in either of its directions of movement free and unrestricted movement of the element 65 to rotate the shaft 31 is obtained.

For the purpose of moving the clutching element 65 -to the right to a position such that the projection 64 on the actuating member l8 extends between the fingers 10 and 11 there is provided a small relay or clutch magnet 12 mounted on an inturned portion 59 of the frame side member 36 by means of a screw 14. Pivotally mounted at ,15 in a slot formed in the member 36 is an armature 18 having mounted thereon an arm 11. This arm 11 is slotted at its lower end to form two fingers 19 and 80 which extend over the shaft 31 and are adapted to engage the left end of the shank 69 forming a part of the clutching element 65. The frame 34, and more particularly the side member 36 thereof, is formed of magnetic material, such, for example, as iron, whereby a substantially closed magnetic circuit, including the armature 36 is provided for the flux produced when the magnet 12 is energized. For purposes of control there is mounted on the frame side member 36 a contact spring assembly at, comprising two or more contact springs clamped between insulating members as shown, and secured to the frame member 36 by a screw 82. The making and breaking of contact between the two springs comprising the assembly 8| is under the control of an arm 82 formed integrally with the armature 16 and provided with an insulating cap 83 for engaging the lower end of the right hand spring included in the spring assembly. In order to hold the shaft 31 and the segments carried thereby operated independently of the condition of the magnet 12 and following the energization of this magnet and one or the other of the magnets 23 and 24, the projection 54 is preferably made of square or triangular cross section and the inner opposite sides of the fingers 10 and 1| are provided with V-shaped grooves for lockingly engaging the opposite edges of the projection 64. By this arrangement the clutching element 65 may be held clutched to the projection 64 even though the magnet 12 is deenergized so long as the energized one of the magnets 23 and 24 is not deenerglzed.

In the operation of the switching unit described above and with the elements thereof in the positions illustrated in Figs. 1, 2, 3 and 4, if it be desired to connect the lines incoming to the switching unit l3 to the group of lines outgoing therefrom which terminate at the set of wipers including the wipers 5i, the magnet 12 is first energized to bring the actuating member i8 into driving relationship with the shaft 31. Thus, when the magnet 12 is energized, it attracts by the spring 6|.

lts armature 16 to make contact between the two springs of the assembly 8| and to pivot the arm 11 counterclockwise, thereby to slide the clutching element 65 along the shaft 31 against the bias of the spring 61 until it stands in a position such that the fingers in and II of the arm II have extending therebetween the projection Bl mounted on the actuating member it. From a consideration of Figs. 3 and 4, it will be seen that the contact segments 40 must be rotated in a counterclockwise direction in order to connect the lines incoming to the unit to the outgoing lines terminating at the wipers 5|. This means, of course, that the actuating member I! must be moved to the right from the position shown in Fig. 4 and to the left from the position shown in Fig. l, and consequently requires that the operating magnet 23 be energized. When this occurs, the finger 64 engages with the finger III of the clutching element 65 to rotate the shaft 31 in a counterclockwise direction and bring the contact segments l into engagement with their -respective associated wipers il thereby to connect the lines incoming to the unit to the lines terminating at these wipers. The operating magnet 2| is maintained energized so long as the connection between these lines is desired. In this connection it is pointed out that the contact springs included in the assembly Bl may be utilized in completing holding circuits for maintaining either or both of the magnets I2 and 23 energized when the unit is in use. However, it is only necessary to maintain the magnet 23 energized in order to retain the unit in its operated position, as previously pointed out. To restore the ele ments of the unit to normal it is only necessary to deenergize the magnet 23, whereupon the clutching element 65 is disengaged from the actuating member l8 under the force exerted by the spring 61 subsequent to the return of the member I8 to its normal position by virtue of the force exerted thereon by the spring 18. As explained above, when the clutching element 65 is disengaged from the actuating member It, the shaft 31 and the commutating segments ll) car ried thereby are restored to their normal positions through the force exerted on the shaft 31 From the preceding description it will be understood that if it is desired to connect the lines incoming to the switching unit to the lines outgoing therefrom which terminate at the wipers 52, the exact sequence of operations described above is followed with the exception that the operating magnet 21 is energized rather than the magnet 23.

As noted previously, the actuating member I8 is arranged selectively to operate the circuit controlling elements embodied in all of the switching units mounted within the section ll of the frame [0. This is accomplished by providing projections. corresponding to the projection 64 for the unit ii, at correctly spaced intervals along the actuating member II, which projections are adapted individually to cooperate with clutching elements individually included in each of the switching units and corresponding to the element 65 of the unit It, when the units are mounted in their correct positions within the section II of the frame I 9.

Although the switching units It, ll, ll, etc., may be constructed of any given size it is specifically contemplated that each thereof shall have an outgoing line capacity of forty lines of three conductors each. Obviously a unit of this capacity requires sixty wipers i, sixty wipers 52,

and sixty contact segments ll. Where, as in the system disclosed in the above referred to copending application of applicant, only a single incoming line to each unit is provided, three multiples must be carried between the segments 40 and connected to the conductors of this line.

While there has been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made in the structure thereof, and it is contemplated in the appended claims to cover all such modifications as fall within the true spirit and scope of the invention.

I claim:

1. Switching apparatus comprising a plurality of switching units each including a circuit controlling element comprising a rotatable shaft, a member having a normal position and movable to an oil-normal position to actuate said shafts, said shafts normally being non-responsive to movement of said member to said off-normal position, clutch projections on said member and corresponding to said units, a clutching element mounted on each of said shafts normally restrained in one position and having fingers adapted to cooperate with the associated clutch proiection'to establish a driving connection between the shaft and said member, a clutch magnet included in each unit for moving the clutching element of the same unit into'clutching relation with its associated clutch projection, a magnet adapted to be energized to move said member from said normal position to said off-normal position, and means for returning said member to its normal position following the energization and subsequent deenergization of said magnet.

2. Switching apparatus comprising a plurality of switching units each including a circuit controlling element selectively movable from a normal position in either of two directions, a movable member for actuating said elements, said elements normally being non-responsive to movement of said member, means for selectively associating said elements with said member to be actuated thereby, means for moving said member in one direction to move any of said elements associated therewith from the normal position in one of said directions of movement, and means for moving said member in another direction to move any of said elements associated therewith from the normal position in the other of said directions of movement.

3. Switching apparatus comprising a plurality of switching units each including two groups of wipers, a circuit controlling element and contact segments mounted on said element, each of said elements being movable in two directions from a normal position to either of two of!- normal positions to bring the segments mounted thereon into engagement with the respective associated wipers of one or the other of its assoelated wiper groups, a movable member for actuating said elements, said elements normally being non-responsive to movement of said member, means for selectively associating said elements with said member to be actuated thereby, means for moving said member in one direction to move any of the elements associated therewith in one of said directions of movement from the normal position to one of said ofi-normal positions, and means for moving said member in another direction to move any of said elements associated therewith in the other 0! said directions or moveamazes ment from the normal position to the other of said off-normal positions.

4. Switching apparatus comprising a plurality of switching units each including two groups of wipers, a circuit controlling element and contact segments mounted on said element, each of said elements being movable in two directions from a normal position to either of two off-normal positions to bring the segments mounted thereon into engagement with the respective associated wipers of one or the other of its associated wiper groups, a movable member for actuating said elements, said elements normally being nonresponsive to movement of said member, mean for selectively associating said elements with said member to be actuated thereby, said last-mentional means comprising a clutch mechanism included in each unit and a clutch magnet included in each unit for operating the clutch mechanism of the .same unit, means for moving said member in one direction to move any of the elements associated therewith in one of said directions of movement from the normal position to one of said ofl-normal positions, and means for moving said member in another direction to move any of said elements associated therewith in the other of said directions of movement from the normal position to the other of said off-normal positions.

5. Switching apparatus comprising a plurality of switching units each including two groups of wipers, a rotatable shaft and contact segments mounted on said shaft; each of said shafts being rotatable in one direction from a normal position to one off-normal position to bring the segments mounted thereon into engagement with the respective associated wipers of one of its associated wiper groups and being rotatable in the other direction from said normal position to a second oil-normal position to bring the segments mounted thereon into engagement with the respective associated wipers of the other of its associated wiper groups, a movable member for actuating said shafts, said shafts normally being non-responsive to movement of said member, means for selectively associating said shafts with said member to be actuated thereby, means for moving said member in one direction to rotate any of the shafts associated in driving relationship therewith in one of said directions from the normal position to one of said off-normal positions, and means for moving said member in another direction to rotate any of the shafts associated in driving relationship therewith in the other of said directions from the normal position to the other of said oil-normal positions.

6. Switching apparatus comprising a plurality of switching units each including two groups of wipers, a rotatable shaft and contact segments mounted on said shaft; .each of said shafts being rotatable in one direction from a normal position to one off-normal position to bring the segments mounted thereon into engagement with the respective associated wipers of one of its associated wiper groups and being rotatable in the other direction from said normal position to a second off-normal position to bring the segments mounted thereon into engagement with the respective associated wipers of the other of its associated wiper groups, a movable member for actuating said shafts, said shafts normally being non-responsive to movement of said member, means for selectively associating said shafts with said member to be actuated thereby, said last-mentioned means comprising a clutch mechanism included in each unit and a clutch magnet included in each unit for operating the clutch mechanism of the same unit, means for moving said member in one direction to rotate any of the shafts associated in driving relationship therewith in one of said directions from the normal position to one of said off-normal positions, and means for moving said member in another direction to rotate any of the shafts associated in driving relationship therewith in the other of said directions from the normal position to the other of said ofi-normal positions.

'7, Switching apparatus comprising a plurality of switching units each including two groups of wipers, a rotatable shaft and contact segments mounted on said shaft; each of said shafts being rotatable in one direction from a normal position to one off-normal position to bring the segments mounted thereon into engagement with the respective associated wipers of one of its associated wiper groups and being rotatable in the other direction from said normal position to a second off-normal position to bring the segments mounted thereon into engagement with the respective associated wipers of the other of its associated wiper groups, a. movable member for actuating said shafts, said shafts normally being non-responsive to movement of said member, clutch projections on said member and corresponding to said units, a clutching element mounted on each of said shafts normally restrained in one position and having fingers adapted to cooperate with the associated clutch projection to establish a driving connection between the shaft and said member, a clutch magnet included in each unit for moving the clutching element of the same unit into clutching relation with its associated clutch projection, means for moving said member in one direction to rotate any of the shafts associated in driving relationship therewith in one of said directions from the normal position to one of said ofil-normal positions, and means for moving said member in another direction to rotate any of the shafts associated in driving relationship therewith in the other of said directions from the normal position to the other of said off-normal positions.

8. Switching apparatus comprising a plurality of switching units each including two groups of wipers, a rotatable shaft and contact segments mounted on said shaft; each of said shafts being rotatable in one direction from a normal position to one off-normal position to bring the segments mounted thereon into engagement with the respective associated wipers of one of its associated wiper groups and being rotatable in the other direction from said normal position to a second off-normal position to bring the segments mounted thereon into engagement with the respective associated wipers of the other of its associated wiper groups, a movable member for actuating said shafts, said shafts normally being non-responsive to movement of said member,

clutch projections on said member and corresponding to said units, a clutching element mounted on each of said shafts normally restrained in one position and having fingers adapted to cooperate with the associated clutch projection to establish a driving connection between the shaft and said member, a clutch magnet included in each unit for moving the clutching element of the same unit into clutching relation with its associated clutch projection, a magnet adapted to be energized to move said actuating member in one direction thereby to 15 rotateanyofthesbaftsassociatedindriving relationship therewith in one of said directions of movement from the normal position to one of said off-normal positions, a second magnet adapted to be energized to move said actuating member in a second direction thereby to rotate any of the shafts associated in driving relationship therewith in the other of said directions from the normal position to the other of said off-normal positions, and means for returning said actuating member to its normal position following the energization and subsequent deenergization of. either of said magnets.

9. Switching apparatus comprising a switching unit including a circuit controlling element selectively movable in either of two opposite directions, a movable member for actuating said element, said element normally being non-responsive to movement of said member, means for associating said element with said member to be actuated thereby, means for moving said member in-one direction to move said element, when associated with said member, in one of said directions of movement, and means for moving said member in another direction of movement to move said element, when associated with said member, in the other of said directions of movement.

10. Switching apparatus comprising a switching unit including a circuit controlling element selectively movable in eitherof two directions, a movable member for actuating said element, said element normally being non-responsive to movement of said member, means for associating said element with said member to be actuated thereby, said last-mentioned means comprising a clutch mechanism included in said unit and a clutch magnet included in said unit for operating said clutch mechanism, means for moving said member in one direction to move said element, when associated with said member, in one of said directions, and means for moving said member in another direction of movement to move said element, when associated with said member, in the other of said directions of movement.

ll. Switching apparatus comprising a plurality of switching units each including a circuit-controlling element selectively movable in either of two directions, an operating bar mounted for movement from a normal position in either direction along its longitudinal axis to actuate said elements in their respectivetwo directions greases of movement, said elements normally being nonr'esponsive to movement of said bar, means for selectively said elements with said bar to be actuated thereby, means for moving said bar from its normal position longitudinally in one direction to move any of said elements associated therewith in one of the two directions of movement thereof, means for moving said her from said normal position longitudinally in the other direction to move any of said elements associated therewith in the other of the two directions of movement thereof, and means normally restraining said bar in said normal position.

12. Switching apparatus comprising a frame, a plurality of switching units mounted on said frame, each of said units including a circuit-controlling element comprising a rotatable shaft selectively rotatable in either of two directions, said shafts being arranged in parallel and extending in the same directlon a clutching element slidably mounted on one and the same end of each of said shafts and normally restrained in one position, each of said clutching elements including a pair of fingers, an operating bar slidably mounted on said frame and arranged to be moved from a normal position in either of two directions along its longitudinal axis and transversely with respect to said shaft, clutch projections extending from said bar at spaced intervals and individually corresponding to the clutching elements of said switching units, a clutch magnet included in each unit for moving the clutching element of the same unit from said one position to bring the fingers of the associated clutching element into clutching relation with the corresponding clutch projection, a magnet adapted to be energized to move said operating bar from its normal position longitudinally in one direction thereby to rotate any of the shafts associated in driving relationship therewith in one of their two directions of movement, a second magnet adapted to be energized to move said operating bar from said normal position longitudinally in the other direction thereby to rotate any of the shafts associated in driving relationship therewith in the other of their two directions of movement, and means for returning said operating bar to its normal position following the energization and subsequent deenergization of either of said magnets.

JOHN E. OBTLINE.

CERTIFICATE OF CORRECTION. Patent No. 2,115,572. January 10, 1959.

JOHN E. OS'I'LINE.

It isherehy certified that error appears in the printed specification of the aboye numbered patent requiring correctionas follows: Page 5,1irst column, 11116 5 claim for the word "mean" read means; and second column, line 12, ciaimT, for "offi-normal" read off-normal; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 7th day of March, A. D. 1959.

' 1 I Henry Van Ar sdale.

(Seal) Acting Commissioner of Patents. 

